Multi-component system containing solvents, hardenable by thermal and actinic radiation and the use thereof

ABSTRACT

A solvent-containing multicomponent system curable thermally and with actinic radiation (dual cure) and comprising
     (A) at least one component comprising
       (A1) at least one constituent containing at least 1.8 meq/g of isocyanate-reactive functional groups,   (A2) at least one constituent containing at least 1.8 meq/g of isocyanate-reactive functional groups and at least one functional group having at least one bond which can be activated with actinic radiation, and   
       (B) at least one component comprising at least one polyisocyanate (B1);
 
and its use as a coating material, adhesive or sealing compound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase Application of InternationalPatent Application PCT/EP01/11311 filed 01, Oct. 2001, which claimspriority on DE 100 48 847.1, filed Oct. 2, 2000.

The present invention relates to a novel solvent-containingmulticomponent system curable thermally and with actinic radiation. Thepresent invention additionally relates to the use of the novelmulticomponent system as a coating material, adhesive or sealingcompound. The present invention further relates to the use of the novelcoating materials for automotive OEM finishing, automotive refinishing,the coating of furniture, doors, windows or constructions in theinterior and exterior sector, and also for industrial coating, includingcoil coating, container coating and the coating or impregnation ofelectrical components.

Here and below, actinic radiation is electromagnetic radiation such asnear infrared (NIR), visible light, UV radiation or x-rays, especiallyUV radiation, or corpuscular radiation such as electron beams.

Among those in the art, curing with heat and actinic radiation is alsoreferred to for short as dual cure.

A dual-cure multicomponent system is known, for example, from EuropeanPatent Application EP 0 928 800 A1. It comprises a urethane(meth)acrylate containing free isocyanate groups and (meth)acryloylgroups, a photoinitiator and an isocyanate-reactive compound, especiallya polyol or polyamine. A constituent which [lacuna] bothisocyanate-reactive functional groups and functional groups having atleast one bond which can be activated with actinic radiation are notused. Although this dual-cure coating material offers the possibility ofvarying the profiles of properties of coating material and coating andof tailoring them to different end uses, its flash-off time is still toolong and its initial hardness in the shadow zones of three-dimensionalsubstrates of complex shape, which are not reached by the actinicradiation without the use of relatively expensive apparatus, is too low.

Moreover, dual-cure multicomponent systems are known from German PatentApplication DE 198 18 735 A1. These systems necessarily comprise

-   -   compounds (A) having one or more free-radically polymerizable        double bonds and further comprising at least one other        functional groups which is reactive in the sense of an addition        reaction and/or condensation reaction, and    -   compounds (B) having one or more free-radically polymerizable        double bonds and further comprising at least one other        functional group which is reactive in the sense of an addition        reaction and/or condensation reaction, the additional reactive        functional group being complementary or reactive with respect to        the additional reactive functional groups of the compounds (A).

In addition, they may comprise at least one monomeric, oligomeric and/orpolymeric compound (C) having at least one functional group which isreactive in the sense of an addition reaction and/or condensationreaction with respect to the functional groups of the compounds (A) or(B) that are present in addition to the free-radically polymerizabledouble bonds.

The advantages set out in the patent application, which are purportedlypossessed by all of the systems described therein, however, stop atgeneral indications and are not reinforced by a specific example.Leaving this aside, there is no statement of the minimum amounts inwhich the additional reactive functional groups should be present in thecompounds.

It is an object of the present invention to find a new dual-curemulticomponent system from which the disadvantages of the prior art arenow absent and which instead has a low flash-off time. Moreover, theintention is that the coatings produced using this system should have ahigh initial hardness, even in the problematic shadow zones ofthree-dimensional substrates of complex shape.

Moreover, the new dual-cure multicomponent system should be suitableboth as a coating material and as an adhesive and sealing compound.

Furthermore, the new coating material should be outstandingly suitablefor automotive OEM finishing, automotive refinishing, the coating offurniture, doors, windows or constructions in the interior and exteriorsector, and also for industrial coating, including coil coating,container coating and the coating or impregnation of electricalcomponents.

The coatings, adhesive films and seals produced from the new dual-curemulticomponent system should possess high scratch resistance, very goodchemical, gasoline, solvent and etch resistance, and very goodweathering stability and should not show any cracks.

The adhesive films and seals should exhibit a durable bond strength and,respectively, a durable sealing capacity even under extreme and/orrapidly changing climatic conditions.

Furthermore, the coatings should be outstandingly suitable as clearcoatsas part of multicoat color and/or effect coating systems. The newclearcoats should have a high initial hardness, even in the problematicshadow zones of three-dimensional substrates of complex shape.

Accordingly, we have [lacuna] the novel solvent-containingmulticomponent system curable thermally and with actinic radiation (dualcure) and comprising

-   (A) at least one component comprising    -   (A1) at least one constituent containing at least 1.8 meq/g of        isocyanate-reactive functional groups,    -   (A2) at least one constituent containing at least 1.8 meq/g of        isocyanate-reactive functional groups and at least one        functional group having at least one bond which can be activated        with actinic radiation, and-   (B) at least one component comprising at least one polyisocyanate    (B1).

In the text below, the novel solvent-containing multicomponent systemcurable thermally and with actinic radiation is referred to [lacuna] the“multicomponent system of the invention”.

The component (A) suitable for the multicomponent system of theinvention comprises at least one constituent (A1) containing at least1.8, preferably at least 2.0, and in particular at least 2.1, meq/g ofisocyanate-reactive functional groups.

Examples of suitable isocyanate-reactive functional groups are thiol,primary or secondary amino, imino or hydroxyl groups, especiallyhydroxyl groups.

The constituent (A1) may be of low molecular mass, oligomeric orpolymeric. Preferably it is oligomeric or polymeric.

The basic structures of the low molecular mass constituents (A1) are notcritical but instead may derive from any of a very wide variety oforganic compound classes. Examples of suitable classes of compound arealkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,cycloalkylaryl, arylalkyl and/or arylcycloalkyl compounds with orwithout heteroatoms such as oxygen, nitrogen, sulfur, silicon orphosphorus and optionally carrying further substituents which, however,must not react during the preparation of the constituents, their storageand/or their use with the bonds which can be activated with actinicradiation.

The basic structures of the oligomeric or polymeric constituents (A1)are likewise not critical and may derive from any of a wide variety ofoligomer and polymer classes. Examples of suitable oligomer and polymerclasses are random, alternating and/or block linear and/or branchedand/or comb (co)polymers of ethylenically unsaturated monomers, orpolyaddition resins and/or polycondensation resins. Regarding theseterms, reference is made for further details to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, page 457,“Polyaddition” and “Polyaddition resins (polyadducts)”, and also pages463 and 464, “Polycondensates”, “Polycondensation” and “Polycondensationresins”. As regards any substituents which may be present, the remarksmade above apply accordingly.

Examples of highly suitable (co)polymers (A1) are poly(meth)acrylatesand partially hydrolyzed polyvinyl esters.

Examples of highly suitable polyaddition resins and/or polycondensationresins (A1) are polyesters, alkyds, polyurethanes, polylactones,polycarbonates, polyethers, epoxy resin-amine adducts, polyureas,polyamides or polyimides.

In accordance with the invention, the (meth)acrylate copolymers,especially those containing hydroxyl groups, have particular advantagesand in accordance with the invention are used with particular preferenceas constituents (A1).

The (meth)acrylate copolymers (A1) are polymers which are known per se.Their preparation has no special features as to method but instead takesplace with the aid of the methods customary and known in the plasticsfield of the continuous or discontinuous free-radically initiatedcopolymerization in bulk, solution, emulsion, miniemulsion ormicroemulsion under atmospheric pressure or superatmospheric pressure instirred vessels, autoclaves, tube reactors, loop reactors or Taylorreactors at temperatures from 50 to 200° C.

Examples of suitable (meth)acrylate copolymers (A1) and copolymerizationmethods are described in patent applications DE 197 09 465 A1, DE 197 09476 A1, DE 28 48 906 A1, DE 195 24 182 A1, DE 198 28 742 A1, DE 196 28143 A1, DE 196 28 142 A1, EP 0 554 783 A1, WO 95/27742, WO 82/02387 andWO 98/02466.

In component (A), the constituents (A1) are present in widely varyingamounts. Preferably, the component comprises the constituents (A1) in anamount of from 5 to 60, more preferably from 6 to 55 and in particularfrom 7 to 50% by weight, based in each case on component (A).

Additionally, component (A) comprises at least one, especially one,constituent (A2) having at least 1.8, preferably at least 2.0 and inparticular at least 2.1, meq/g of isocyanate-reactive functional groupsand at least one, preferably at least two and in particular three,functional groups having at least one bond which can be activated withactinic radiation.

Examples of suitable bonds which can be activated with actinic radiationare carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen,carbon-nitrogen, carbon-phosphorus or carbon-silicon single bonds ordouble bonds. Of these, the double bonds, especially the carbon-carbondouble bonds (“double bonds”), are employed with preference.

Very suitable double bonds are present, for example, in (meth)acrylate,ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester,ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isoprenyl,isopropenyl, allyl or butenyl groups; ethenylarylene ether,dicyclopentadienyl ether, norbornenyl ether, isoprenyl ether,isopropenyl ether, allyl ether or butenyl ether groups; orethenylarylene ester, dicyclopentadienyl ester, norbornenyl ester,isoprenyl ester, isopropenyl ester, allyl ester or butenyl ester groups.Of these, (meth)acrylate groups, especially acrylate groups, are ofparticular advantage and are therefore used with very particularpreference in accordance with the invention.

The constituent (A2) may be of low molecular mass, oligomeric orpolymeric. Preferably it is oligomeric or polymeric.

The basic structure of the constituent (A2) is not critical. It ispossible to use the basic structures described above for the constituent(A1).

Accordingly, the constituents (A2) come from the oligomer and/or polymerclasses of the (meth)acryloyl-functional (meth)acrylic copolymers,polyether acrylates, polyester acrylates, polyesters, epoxy acrylates,urethane acrylates, amino acrylates, melamine acrylates, siliconeacrylates and phosphazene acrylates and the corresponding methacrylates.It is preferred to use binders (a1) which are free from aromaticstructural units. Use is therefore made preferably of urethane(meth)acrylates, phosphazene (meth)acrylates and/or polyester(meth)acrylates, with particular preference of urethane (meth)acrylates,especially aliphatic urethane (meth)acrylates.

The preparation of urethane (meth)acrylate (A2) having terminal and/orlateral double bonds has no special features in terms of its method butinstead is described in detail in patent applications and patents DE 19645 761 A, WO 98/10028, EP 0 742 239 A1, EP 0 661 321 B1, EP 0 608 021B1, EP 0 447 998 B1, and EP 0 462 287 B1. Moreover, these constituentsare commercially customary products and are sold, for example, under thebrand name Rahn® 99-664 by the company Rahn.

In component (A), the constituents (A2) are present in widely varyingamounts. Preferably, component [lacuna] comprises (the constituents (A1)in an amount of from 10 to 60, more preferably from 15 to 55, and inparticular from 20 to 50% by weight, based in each case on component(A).

Furthermore, component (A) of the multicomponent system may furthercomprise customary and known additives in effective amounts. Theessential factor is that the additives do not inhibit or prevententirely the dual-cure crosslinking reactions.

Examples of suitable additives are nanoparticles, reactive diluentscurable thermally or with actinic radiation, low-boiling organicsolvents and high-boiling organic solvents (“long solvents”), water, UVabsorbers, light stabilizers, free-radical scavengers, thermally labilefree-radical initiators, photoinitiators and photocoinitiators,crosslinking agents as used in one-component systems, thermalcrosslinking catalysts, devolatilizers, slip additives, polymerizationinhibitors, defoamers, emulsifiers, wetting agents, dispersants,adhesion promoters, levelling agents, film-forming auxiliaries, sagcontrol agents (SCAs), rheology control additives (thickeners), flameretardants, siccatives, dryers, antiskinning agents, corrosioninhibitors, waxes, flatting agents, precursors of organically modifiedceramic materials, or additional binders.

Examples of suitable thermally curable reactive diluents arepositionally isomeric diethyloctanediols or hydroxyl-containinghyperbranched compounds or dendrimers, as described for example inGerman Patent Applications DE 198 05 421 A1, DE 198 09 643 A1, and DE198 40 405 A1.

Examples of suitable reactive diluents curable with actinic radiationare those described in Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, New York, 1998, on page 491 under the entry “reactivediluents” or in column 7 lines 1 to 26 of DE 198 18 715 A1, or reactivediluents having at least 5, especially 5, bonds which can be activatedwith actinic radiation in their molecule, such as dipentaerythritolpentacrylate, for example.

Examples of suitable low-boiling organic solvents and high-boilingorganic solvents (“long solvents”) are ketones such as methyl ethylketone, methyl isoamyl ketone or methyl isobutyl ketone, esters such asethyl acetate; butyl acetate, ethyl ethoxypropionate, methoxypropylacetate or butyl glycol acetate, ethers such as dibutyl ether orethylene glycol, diethylene glycol, propylene glycol, dipropyleneglycol, butylene glycol or dibutylene glycol dimethyl, diethyl ordibutyl ether, N-methylpyrrolidone or xylenes or mixtures of aromaticand/or aliphatic hydrocarbons such as Solventnaphtha®, mineral spirit135/180, dipentenes or Solvesso®.

Examples of suitable thermally labile free-radical initiators areorganic peroxides, organic azo compounds or C-C-cleaving initiators suchas dialkyl peroxides, peroxocarboxylic acids, peroxodicarbonates, orperoxide esters, hydroperoxides, ketone peroxides, azo dinitriles orbenzpinacol silyl ethers.

Examples of suitable crosslinking catalysts are dibutyltin dilaurate,dibutyltin dioleate, lithium decanoate, zinc octoate or bismuth saltssuch as bismuth lactate or bismuth dimethylolpropionate.

Examples of suitable photoinitiators and coinitiators are described inRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,1998, pages 444 to 446.

Examples of suitable additional crosslinking agents as used inone-component systems are amino resins, as described for example inRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, page 29,“Amino resins”, in the text book “Lackadditive” [Additives for Coatings]by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, pages 242 ff.,in the book “Paints, coatings and solvents”, second, completely revisededition, D. Stoye and W. Freitag (eds.), Wiley-VCH, Weinheim, N.Y.,1998, pages 80 ff., in patents U.S. Pat. No. 4,710,542 A1 and EP-B-0 245700 A1, and in the article by B. Singh and coworkers,“Carbamylmethylated Melamines, Novel Crosslinkers for the CoatingsIndustry” in Advanced Organic Coatings Science and Technology Series,1991, Volume 13, pages 193 to 207; carboxyl-containing compounds orresins, as described for example in patent DE 196 52 813 A1; resins orcompounds containing epoxide groups, as described for example in patentsEP 0 299 420 A1, DE 22 14 650 B1, DE 27 49 576 B1, U.S. Pat. No.4,091,048 A and U.S. Pat. No. 3,781,379 A; blocked polyisocyanates, asdescribed for example in patents U.S. Pat. No. 4,444,954 A, DE 196 17086 A1, DE 196 31 269 A1, EP 0 004 571 A1 and EP 0 582 051 A1; and/ortris(alkoxycarbonylamino)triazines as described in patents U.S. Pat. No.4,939,213 A, U.S. Pat. No. 5,084,541 A, U.S. Pat. No. 5,288,865 A and EP0 604 922 A1.

Examples of suitable devolatilizers are diazadicycloundecane andbenzoin.

Examples of suitable emulsifiers are nonionic emulsifiers, such asalkoxylated alkanols, polyols, phenols and alkylphenols, or anionicemulsifiers such as alkali metal salts or ammonium salts ofalkanecarboxylic acids, alkanesulfonic acids, and sulfo acids ofalkoxylated alkanols, polyols, phenols and alkylphenols.

Examples of suitable wetting agents are siloxanes, fluorine compounds,carboxylic monoesters, phosphoric esters, polyacrylic acids and theircopolymers, or polyurethanes.

An example of a suitable adhesion promoter is tricyclodecanedimethanol.

Examples of suitable film-forming auxiliaries are cellulose derivativessuch as cellulose acetobutyrate (CAB).

Examples of suitable transparent fillers are those based on silicondioxide, aluminum oxide or zirconium oxide; for further details,reference is made to Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, 1998, pages 250 to 252.

Examples of suitable sag control agents are ureas, modified ureas and/orsilicas, as described for example in the literature references EP 0 192304 A1, DE 23 59 923 A1, DE 18 05 693 A1, WO 94/22968, DE 27 51 761 C1,WO 97/12945 or “farbe+lack”, 11/1992, pages 829 ff.

Examples of suitable rheology control additives are those known frompatents WO 94/22968, EP 0 276 501 A1, EP 0 249 201 A1 and WO 97/12945;crosslinked polymeric microparticles, as disclosed for example in EP 0008 127 A1; inorganic phyllosilicates such as aluminum-magnesiumsilicates, sodium-magnesium and sodium-magnesium-fluorine-lithiumphyllosilicates of the montmorillonite type; silicas such as Aerosils;or synthetic polymers containing ionic and/or associative groups such aspolyvinyl alcohol, poly(meth)acrylamide, poly(meth)acrylic acid,polyvinylpyrrolidone, styrene-maleic anhydride copolymers orethylene-maleic anhydride copolymers and their derivatives orhydrophobically modified ethoxylated urethanes or polyacrylates.

An example of a suitable flatting agent is magnesium stearate.

Examples of suitable precursors of organically modified ceramicmaterials are hydrolyzable organometallic compounds, especially ofsilicon and aluminum.

Further examples of the above-listed additives and also examples ofsuitable UV absorbers, free-radical scavengers, levelling agents, flameretardants, siccatives, dryers, antiskinning agents, corrosioninhibitors and waxes (B) are described in detail in the text book“Lackadditive” by Johan Bieleman, Wiley-VCH, Weinheim, N.Y., 1998.

The preparation of component (A) for use in accordance with theinvention has no special features but instead takes place in a customaryand known manner by mixing of the above-described constituents inappropriate mixing equipment such as stirred vessels, dissolvers,stirred mills or extruders.

Component (B) of the multicomponent system of the invention comprises atleast one polyisocyanate (B1).

The polyisocyanates (B1) contains on average at least 2.0, preferablymore than 2.0, and in particular more than 3.0 isocyanate groups permolecule. Basically, there is no upper limit on the number of isocyanategroups; in accordance with the invention, however, it is of advantage ifthe number does not exceed 15, preferably 12, with particular preference10, with very particular preference 8.0, and in particular 6.0.

Examples of suitable polyisocyanates (B1) are isocyanato-containingpolyurethane prepolymers which may be prepared by reacting polyols withan excess of diisocyanates and are preferably of low viscosity.

Examples of suitable diisocyanates are isophorone diisocyanate (i.e.,5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane),5-isocyanato-1-(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)-cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-iso-cyanatobut-1-yl)-cyclohexane,1,2-diisocyanatocyclobutane, 1,3-diisocyanatocyclobutane,1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane,1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane,1,4-diisocyanatocyclohexane, dicyclohexylmethane 2,4′-diisocyanate,trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylene diisocyanate (HDI), ethylethylenediisocyanate, trimethylhexane diisocyanate, heptamethylene diisocyanateor diisocyanates derived from dimeric fatty acids, as sold under thecommercial designation DDI 1410 by the company Henkel and described inpatents WO 97/49745 and WO 97/49747, especially2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or 1,2-, 1,4-or 1,3-bis(isocyanatomethyl)cyclohexane, 1,2-, 1,4- or1,3-bis(2-isocyanatoeth-1-yl)cyclohexane,1,3-bis(3-isocyanatopropy-1-yl)cyclohexane, 1,2-, 1,4- or1,3-bis(4-isocyanatobut-1-yl)cyclohexane or liquidbis(4-isocyanatocyclohexyl)methane with a trans/trans content of up to30% by weight, preferably 25% by weight and in particular 20% by weight,as described in patent applications DE 44 14 032 A1, GB 1220717 A1, DE16 18 795 A1 and DE 17 93 785 A1, preferably isophorone diisocyanate,5-isocyanato-1-(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-isocyanatobut-1-yl)cyclohexane or HDI, especially HDI.

It is also possible to use polyisocyanates (B1) containing isocyanurate,biuret, allophanate, iminooxadiazinedione, urethane, urea, carbodiimideand/or uretdione groups, which are prepared in a customary and knownmanner from the diisocyanates described above. Example of suitablepreparation techniques and polyisocyanates are known, for example, frompatents CA 2,163,591 A, U.S. Pat. No. 4,419,513, U.S. Pat. No. 4,454,317A, EP 0 646 608 A, U.S. Pat. No. 4,801,675 A, EP 0 183 976 A1, DE 40 15155 A1, EP 0 303 150 A1, EP 0 496 208 A1, EP 0 524 500 A1, EP 0 566 037A1, U.S. Pat. No. 5,258,482 A1, U.S. Pat. No. 5,290,902 A1, EP 0 649 806A1, DE 42 29 183 A1 and EP 0 531 820 A1.

The amount of the polyisocyanates (B1) in component (B) may vary widely.Primarily it is guided by the viscosity necessary for mixing with theother components. Preferably, the amount is from 20 to 80, morepreferably from 30 to 70, and in particular from 35 to 65% by weight,based on component (B). Component (B) preferably further comprises atleast one of the above-described organic solvents.

Furthermore, component (B) may comprise at least one, especially one,constituent (B2) containing at least one isocyanate group and at leastone functional group having at least one bond which can be activatedwith actinic radiation.

These constituents (B2) are obtainable, as is known, by reacting theabove-described diisocyanates and polyisocyanates (B1) with compoundscontaining at least one, especially one, of the above-describedisocyanate-reactive functional groups and at least one, especially one,bond which can be activated with actinic radiation. Examples of suitablecompounds of this kind are

-   -   2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl,        3-hydroxybutyl, 4-hydroxybutyl, bis(hydroxymethyl)cyclohexane,        neopentyl glycol, diethylene glycol, dipropylene glycol,        dibutylene glycol, and triethylene glycol acrylate,        methacrylate, ethacrylate, crotonate, cinnamate, vinyl ether,        allyl ether, dicyclopentadienyl ether, norbornenyl ether,        isoprenyl ether, isopropenyl ether or butenyl ether;    -   trimethylolpropane di-, glycerol di-, trimethylolethane di-,        pentaerythritol tri- or homopentaerythritol tri-acrylate,        methacrylate, ethacrylate, crotonate, cinnamate, vinyl ether,        allyl ether, dicyclopentadienyl ether, norbornenyl ether,        isoprenyl ether, isopropenyl ether or butenyl ether; or    -   reaction products of cyclic esters, such as        epsilon-caprolactone, for example, and the above-described        hydroxyl-containing monomers; or    -   2-aminoethyl (meth)acrylate and/or 3-aminopropyl (meth)acrylate.

In terms of method, the preparation of these constituents (B2) has nospecial features but instead takes place as described, for example, inEuropean Patent Application EP 0 928 800 A1.

Preparation of component (B) has no special features in terms of itsmethod but instead takes place by the mixing of its constituents. Inorder to establish a low viscosity, component (B) may further be admixedwith at least one of the above-described organic solvents.

Where the multicomponent system of the invention comprises onlycomponents (A) and (B), it constitutes a two-component system. However,different constituents of the individual components (A) and/or (B) maybe stored separately from these components and combined not untilshortly before application to form the multicomponent system. Ingeneral, the two-component system is preferred since it entails lesseffort for its preparation.

The preparation of the multicomponent systems of the invention from theabove-described components (A) and (B) has no special features in termsof its method but instead is carried out with the aid of the customaryand known, above-described mixing equipment and mixing techniques or bymeans of customary two-component or multicomponent metering and mixingunits. Ideally, mixing takes place by hand if permitted by the viscosityof component (A) and (B).

The weight ratio of component (A) to component (B) may vary widely. Itis guided primarily by the functionality and concentration of theabove-described reactive constituents of the components, especially (A1)and (A2) on the one hand and (B1) on the other hand. The skilled workerwill therefore easily be able to determine the optimum volume ratio foreach individual case on the basis of his or her knowledge of the art,with or without the assistance of simple rangefinding tests. The weightratio is preferably from 3:1 to 1:3, more preferably from 2.7:1 to1:2.7, and in particular from 2.5:1 to 1:2.5.

The multicomponent systems of the invention may be used for a very widevariety of purposes. Preferably, they are used as coating materials,adhesives and sealing compounds.

The coating materials, adhesives and sealing compounds of the inventionare used to produce coatings, adhesive films and seals on and/or inprimed and unprimed substrates. The coating materials of the inventionare used in particular to produce clearcoats, especially clearcoats inmulticoat color and/or effect coating systems.

In terms of method, the application of the clearcoat materials of theinvention has no special features but instead may take place by anycustomary application method, such as spraying, knifecoating, brushing,flowcoating, dipping, trickling or rolling, for example. It is preferredto employ spray application methods, such as compressed air spraying,airless spraying, high-speed rotation, electrostatic spray application(ESTA), alone or in conjunction with hot spray applications such ashot-air spraying, for example.

Suitable substrates are surfaces which are not damaged by curing of thecoating materials, adhesives and/or sealing compounds present thereonusing heat and actinic radiation; examples are metals, plastics, wood,ceramic, stone, textile, fiber composites, leather, glass, glass fibers,glass wool, rockwool, mineral-bound and resin-bound building materials,such as plasterboard and cement slabs or roof tiles, and also assembliesof these materials.

Accordingly, the coating materials, adhesives and sealing compounds ofthe invention are also suitable for applications outside of automotiveOEM finishing and automotive refinishing. In this context they areparticularly suitable for the coating, adhesive bonding or sealing offurniture, windows, doors, constructions in the interior and exteriorsector, and for industrial coating, including coil coating, containercoating and the impregnation or coating of electrical components. In thecontext of industrial coatings, they are suitable for coating, adhesivebonding and/or sealing virtually all parts for private or industrialuse, such as radiators, domestic appliances, small metal parts such asnuts and bolts, wheel caps, wheel rims, packaging, or electricalcomponents such as motor windings or transformer windings.

In the case of electrically conductive substrates, it is possible to useprimers which are produced in a customary and known manner from theelectrodeposition coating materials. Both anodic and cathodicelectrodeposition coating materials are suitable for this purpose, butespecially cathodic materials.

The electrodeposition coating or electrodeposition film may beovercoated with a surfacer, which is cured either alone or together withthe electrodeposition film (wet-on-wet technique). Over-coating with asurfacer is carried out in particular in the regions exposed to severemechanical stress, such as by stone chipping, for example.

Examples of suitable cathodic electrodeposition coating materials andalso, where appropriate, of wet-on-wet techniques are described inJapanese Patent Application 1975-142501 (Japanese Laid-openSpecification JP 52-065534 A2, Chemical Abstracts No. 87: 137427) or inthe patents and patent applications U.S. Pat. No. 4,375,498 A, U.S. Pat.No. 4,537,926 A, U.S. Pat. No. 4,761,212 A, EP 0 529 335 A1, DE 41 25459 A1, EP 0 595 186 A1, EP 0 074 634 A1, EP 0 505 445 A1, DE 42 35 778A1, EP 0 646 420 A1, EP 0 639 660 A1, EP 0 817 648 A1, DE 195 12 017 C1,EP 0 192 113 A2, DE 41 26 476 A1, and WO 98/07794.

Similarly, suitable surfacers, especially aqueous surfacers, which arealso known as antistone-chip primers or functional coats, are known fromthe patents and patent applications U.S. Pat. No. 4,537,926 A, EP 0 529335 A1, EP 0 595 186 A1, EP 0 639 660 A1, DE 44 38 504 A1, DE 43 37 961A1, WO 89/10387, U.S. Pat. No. 4,450,200 A, U.S. Pat. No. 4,614,683 Aand WO 94/26827.

It is also possible to coat, adhesively bond or seal primed or unprimedplastics parts made, for example, from ABS, AMMA, ASA, CA, CAB, EP, UF,CF, MF, MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE, UHMWPE, PC, PC/PBT,PC/PA, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM,SMC, BMC, PP-EPDM and UP (abbreviated codes in accordance with DIN7728P1). Unfunctionalized and/or nonpolar substrate surfaces may besubjected prior to coating in a known manner to a pretreatment, such asby plasma or by flaming, or may be provided with a primer.

In accordance with the invention, the clearcoats of the invention areproduced by applying the clearcoat materials of the invention to thesubstrates described above, after which the resultant clearcoat filmsare cured.

In accordance with the invention, the adhesive films and seals of theinvention are produced by applying the adhesives and sealing compoundsof the invention onto and/or into the substrates described above. In thecase of the adhesive bonding of substrates, the surfaces of two or moresubstrates to be bonded are preferably coated with the adhesive of theinvention, after which the surfaces in question are contacted, underpressure if desired, and the resultant adhesive films are cured.

As is known, the production of a multicoat color and/or effect coatingsystem on a primed or unprimed substrate takes place by

-   (1) applying a basecoat material to the substrate,-   (2) drying and/or partly or fully curing the basecoat film,-   (3) applying a clearcoat material to the dried and/or partly cured    basecoat film or to the cured basecoat, and-   (4) jointly curing the clearcoat film with the basecoat film, or    separately curing the clearcoat film.

Examples of suitable basecoat materials are known from patentapplications EP 0 089 497 A1, EP 0 256 540 A1, EP 0 260 447 A1, EP 0 297576 A1, WO 96/12747, EP 0 523 610 A1, EP 0 228 003 A1, EP 0 397 806 A1,EP 0 574 417 A1, EP 0 531 510 A1, EP 0 581 211 A1, EP 0 708 788 A1, EP 0593 454 A1, DE-A-43 28 092 A1, EP 0 299 148 A1, EP 0 394 737 A1, EP 0590 484 A1, EP 0 234 362 A1, EP 0 234 361 A1, EP 0 543 817 A1, WO95/14721, EP 0 521 928 A1, EP 0 522 420 A1, EP 0 522 419 A1, EP 0 649865 A1, EP 0 536 712 A1, EP 0 596 460 A1, EP 0 596 461 A1, EP 0 584 818A1, EP 0 669 356 A1, EP 0 634 431 A1, EP 0 678 536 A1, EP 0 354 261 A1,EP 0 424 705 A1, WO 97/49745, WO 97/49747, EP 0 401 565 A1 and EP 0 817684, column 5, lines 31 to 45.

In general, the surfacer film, topcoat film, basecoat film and clearcoatfilm are applied in a wet film thickness such that curing thereofresults in coats having the film thicknesses advantageous and necessaryfor their functions. In the case of the surfacer film this filmthickness is from 10 to 150, preferably from 15 to 120, with particularpreference from 20 to 100, and in particular from 25 to 90 μm, in thecase of the topcoat it is from 5 to 90, preferably from 10 to 80, withparticular preference from 15 to 60, and in particular from 20 to 50 μm,in the case of the basecoat it is from 5 to 50, preferably from 6 to 40,with particular preference from 7 to 30, and in particular from 8 to 25μm, and in the case of the clearcoats it is from 10 to 100, preferablyfrom 15 to 90, with particular preference from 20 to 80, and inparticular from 25 to 70 μm.

Complete curing can take place after a certain flash-off time. This isused for example for leveling and for the degassing of the applied filmsor for the evaporation of volatile constituents such as solvents orwater. The rest time may be assisted and/or shortened by the use ofelevated temperatures up to 40° C. and/or by blowing the films, providedthis does not entail any damage or alteration to the applied films, suchas premature complete crosslinking, for example. The clearcoats of theinvention have an advantageously short flash-off time of <10, especially<5 minutes. This produces a shortening in the process times overall.

In accordance with the invention the curing takes place with actinicradiation, especially with UV radiation, and/or electron beams. Ifdesired, it may be supplemented by or carried out with actinic radiationfrom other radiation sources. In the case of electron beams, it ispreferred to operate under an inert gas atmosphere. This may be ensured,for example, by supplying carbon dioxide and/or nitrogen directly to thesurface of the applied films.

In the case of curing with UV radiation as well it is possible tooperate under inert gas in order to prevent the formation of ozone.

Curing with actinic radiation is carried out using the customary andknown radiation sources and optical auxiliary measures. Examples ofsuitable radiation sources are high or low pressure mercury vapor lamps,with or without lead doping in order to open up a radiation window of upto 405 nm, or electron beam sources. Their arrangement is known inprinciple and may be adapted to the circumstances of the workpiece andthe process parameters. In the case of workpieces of complex shape suchas automobile bodies, the regions not accessible by direct radiation(shadow regions) such as cavities, folds and other structural undercutsmay be cured using point, small-area or all-round sources, inconjunction with an automatic movement device for the irradiation ofcavities or edges.

The equipment and conditions for these curing methods are described, forexample, in R. Holmes, U.V. and E.B. Curing Formulations for PrintingInks, Coatings and Paints, SITA Technology, Academic Press, London,United Kingdom 1984.

The cure may be effected in stages, i.e., by multiple exposure to lightor actinic radiation. This can also be done alternatingly, i.e., bycuring in alternation with UV radiation and electron beams.

Thermal curing as well has no special features in terms of method butinstead takes place in accordance with the customary and known methodssuch as heating in a forced air oven or irradiation with IR lamps. Asfor curing with actinic radiation, thermal curing may also take place instages. Thermal curing is preferably effected at room temperature orabove room temperature, preferably at temperatures >40° C.,preferably >50° C., for a period of from one minute to several days.

Thermal curing and curing with actinic radiation may be usedsimultaneously or in alternation. Where the two curing methods are usedin alternation, it is possible, for example, to commence with thermalcuring and end with actinic radiation curing. In other cases, it mayprove advantageous to commence and to end with actinic radiation curing.The skilled worker is able to determine the curing method which is mostadvantageous for the particular case in hand, on the basis of hisgeneral knowledge of the art with the assistance, if appropriate, ofsimple preliminary tests.

The coating materials, adhesives and sealing compounds of the inventionhave a high solids content, in combination with low viscosity and a longstability time.

The flash-off time of the multicomponent systems of the invention,especially of the clearcoat material of the invention, prior to curingis very short, so that overall the process times are reduced.

The coatings, adhesive films and seals produced with the aid of themulticomponent systems of the invention, especially the clearcoats ofthe invention, have a high initial hardness even in the shadow regionsof the substrates.

The resultant coatings of the invention, especially the clearcoats andthe multicoat color and/or effect coating systems comprising them,possess high hardness, flexibility and chemical resistance, outstandingleveling, no runs, very good intercoat adhesion, an outstanding overallappearance, very good weathering stability, very high scratch resistanceand abrasion resistance, and very good polishability.

The adhesive films of the invention possess long-term and high bondstrength even under extreme and/or very sharply and rapidly changingclimatic conditions.

The seals of the invention provide long-term and complete sealingagainst chemically aggressive substances.

Consequently, the primed and unprimed substrates of the invention coatedwith at least one coating of the invention, bonded with at least oneadhesive film of the invention and/or sealed with at least one seal ofthe invention possess a particularly long service life in addition tothe advantages set out above, so making them particularly valuable froman economic standpoint.

EXAMPLES AND COMPARATIVE EXPERIMENT Preparation Example 1

The Preparation of a Thermally Curable Methacrylate Copolymer

A steel reactor equipped with stirrer, reflux condenser and two feedvessels was charged with 185.6 parts by weight of ethyl ethoxypropionateand this initial charge was heated with stirring to 160° C.Subsequently, a monomer mixture of 114.1 parts by weight of styrene,136.9 parts by weight of methyl methacrylate, 79.3 parts by weight ofbutyl methacrylate, 109 parts by weight of n-butyl acrylate and 164.1parts by weight of hydroxyethyl methacrylate was metered in at a uniformrate over the course of four hours. Beginning at the same time and inparallel with this monomer mixture, an initiator mixture of 35.8 partsby weight of ethyl ethoxypropionate and 36.2 parts by weight ofdi-tert-butyl peroxide was metered in at a uniform rate. After one hour,initiation was repeated at 110° C. with an initiator mixture of 5.7parts by weight of butyl acetate and 0.5 parts by weight of tert-butylperoxyethylhexanoate. Subsequently, the resultant reaction mixture washeld at 110° C. for one hour. Thereafter, at 80° C., the solution wasadjusted to a solids content of 65% by weight using butyl acetate. Theresultant solution had a viscosity of 15 dpas. The hydroxyl number ofthe methacrylate copolymer was 120 mg KOH/g.

Examples 1 and 2 and Comparative Experiment 1

The Preparation of Inventive Clearcoat Materials (examples 1 and 2) andof a Noninventive Clearcoat Material (Comparative Experiment 1) andTheir use to Produce Multicoat Color and Effect Coating Systems

The inventive clearcoat materials of examples 1 and 2 and thenoninventive clearcoat material of comparative experiment 1 wereprepared by mixing the constituents indicated in table 1. For thispurpose, components (A) and (B) were each mixed with one another in aweight ratio of 2:1 and were subsequently diluted with 10%, based on theclearcoat materials, of a diluent (solvent mixture comprising xylene,solvent naphtha, mineral spirit 135/180, methoxypropyl acetate, butylacetate, butyl glycol acetate, ethyl ethoxypropionate and dipentenes).

TABLE 1 The material composition of the inventive clearcoat materials(examples 1 and 2) and of the noninventive clearcoat material(comparative experiment 1) Comparative Constituent Example 1 Example 2experiment 1 Component (A): Methacrylate copolymer of 30 — 30preparation example 1 Urethane acrylate 1^(a)) 43 — — Polyester acrylate2^(b)) — 30 43 Polyester acrylate 3^(c)) — 43 — Butyl acetate  4.8  4.8 4.8 Ethyl ethoxyproprionate 15 15 15 Methyl isoamyl ketone  2  2  2Byk ® 325^(d))  0.3  0.3  0.3 Byk ® 358^(d))  0.7  0.7  0.7 Tinuvin ®292^(e))  1  1  1 Tinuvin ® 400^(e))  1  1  1 Irgacure ® 184^(f))  1.4 1.4  1.4 Lucirin ® TPO^(f))  0.3  0.3  0.3 Dibutyltin dilaurate (10% 0.5.  0.5  0.5 strength in butyl acetate) Component (B): Desmodur ® N3600^(g)) 56 56 50 Methyl isoamyl ketone 22 22 25 Ethyl ethoxypropionate22 22 25 ^(a))Urethane acrylate 1: commercially customary urethaneacrylate Rahn ® 99–664 from Rahn, acrylate functionality: 3; hydroxylnumber: 120 mg KOH/g, corresponding to 2.14 meq/g; ^(b))Polyesteracrylate 2: Laromer ® 8981 from BASF Aktiengesellschaft, hydroxylnumber: 80 mg KOH/g, corresponding to 1.4 meq/g; ^(c))Polyester acrylate3: Laromer ® 8907 from BASF Aktiengesellschaft, hydroxyl number: 120 mgKOH/g, corresponding to 2.14 meq/g; ^(d))commercially customary levelingagents; ^(e))commercially customary light stabilizers; ^(f))commerciallycustomary photoinitiators; ^(g))commercially customary polyisocyanatebased on hexamethylene diisocyanate, from Bayer AG.

To produce the multicoat color and effect coating systems, sanded steelpanels were first of all coated with a commercially customarytwo-component polyurethane surfacer from BASF Coatings AG. The surfacerwas applied in two spray passes, dried at 60° C. for 30 minutes and thensanded. Subsequently, an aqueous basecoat material was applied in twospray passes and dried at 60° C. for 5 minutes. Thereafter, theclearcoat materials 1 and 2 were applied in two spray passes with aflash-off time of 2.5 minutes in between.

The applied clearcoat films of examples 1 and 2 and the clearcoatmaterial of comparative experiment 1 were flashed off for 5 minutes,dried at 60° C. for 15 minutes and then cured with UV radiation at adose of 1500 mJ/cm². The resultant clearcoats had a film thickness offrom 50 to 60 μm. The multicoat systems of the invention, of examples 1and 2, had an outstanding appearance, which was superior to that of themulticoat system of comparative experiment 1.

To determine the initial hardness, the pendulum hardness of the appliedclearcoat films was measured in accordance with König (pendulumimpacts). The results are given in Table 2. They demonstrate the highinitial hardness of the clearcoats of examples 1 and 2 in comparison tothe initial hardness of the clearcoat of comparative experiment 1.

In a second series of tests, the curing characteristics of the clearcoatmaterials in shadow zones of substrates were simulated by not UV-curingthe test panels described above. The resultant clearcoats of examples 1and 2 were not tacky but instead had a good initial hardness. Incontrast, the clearcoat of comparative experiment 1 was tacky.

TABLE 2 Initial hardness of the clearcoat of example 1 in comparison tothe initial hardness of the clearcoat of comparative experiment 1Pendulum impacts Curing Comparative conditions Example 1 Example 2experiment 1 Test series 1: Curing with UV radiation: after 5 days 105100 88 after 10 days 135 130 123 Test series 1: Curing without UVradiation: after 5 days  67  59  19 after 10 days 101  95  43

1. A multicomponent system curable thermally and with actinic radiation,comprising (A) at least one component comprising (A1) at least oneconstituent comprising an oligomer and/or a polymer each having at least1.8 meq/g of isocyanate-reactive functional groups, (A2) at least oneconstituent comprising an oligomer and/or a polymer each having at least1.8 meq/g of isocyanate-reactive functional groups comprising at leastone functional group having at least one bond activatedable by actinicradiation, and (B) at least one component comprising at least onepolyisocyanate constituent (B1).
 2. The system of claim 1, whereincomponent (B) further comprises at least one constituent (B2) comprisingat least one isocyanate group and at least one functional groupcomprising at least one bond activatable by actinic radiation.
 3. Thesystem of claim 2, wherein the bonds activatable by actinic radiation ofconstituent (A2) and (B2) are selected from the group consisting ofcarbon-hydrogen single bonds, carbon-carbon single bonds, carbon-carbondouble bonds, carbon-oxygen single bonds, carbon-oxygen double bonds,carbon-nitrogen single bonds, carbon-nitrogen double bonds,carbon-phosphorus single bonds, carbon-phosphorus double bonds,carbon-silicon single bonds, carbon-silicon double bonds, and mixturesthereof.
 4. The system of claim 3, wherein the bonds activatable byactinic radiation are carbon-carbon double bonds.
 5. The system of claim4, wherein the carbon-carbon double bonds are present in a functionalgroup selected from the group consisting of (meth)acrylate, ethacrylate,crotonate, cinnamate, vinyl ether, vinyl ester, ethenylarylene,dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl, butenyl,ethenylarylene ether, dicyclopentadienyl ether, norbornenyl ether,isoprenyl ether, isopropenyl ether, allyl ether, butenyl ether,ethenylarylene ester, dicyclopentadienyl ester, norbornenyl ester,isoprenyl ester, isopropenyl ester, allyl ester, butenyl ester, andmixtures thereof.
 6. The system of claim 1, wherein theisocyanate-reactive functional groups are selected from the groupconsisting of thiol, primary amino, secondary amino, imino, hydroxylgroups, and mixtures thereof.
 7. The system of claim 1, whereinconstituent (A1) comprises at least one member selected from the groupconsisting of (co)polymers of ethylenically unsaturated monomers,polyaddition resins, polycondensation resins, and mixtures thereof. 8.The system of claim 1, wherein constituent (A2) comprises on averagethree functional groups comprising at least one bond activatable withactinic radiation per molecule.
 9. The system of claim 1, whereinconstituent (A2) comprises at least one member selected from the groupconsisting of (co)polymers of ethylenically unsaturated monomers,polyaddition resins, polycondensation resins, and mixtures thereof. 10.The system of claim 1, wherein at least one of component (A) orcomponent (B) comprise at least one reactive diluent curable withactinic radiation.
 11. The system or claim 10, wherein the reactivediluent curable with actinic radiation comprises at least 5 bondsactivatable by actinic radiation per molecule.
 12. The system of claim 1which is a coating material, adhesive or sealing compound.
 13. A methodof making a coated substrate, comprising applying the system of claim 12to a substrate selected from the group consisting of automotive OEMfinishing substrates, automotive refinishing substrates, furnituresubstrates, door substrates, window substrates, interior substrates,exterior substrates, industrial coating substrates, coil coatingsubstrates, container substrates, or electrical component substrates,and curing the system.
 14. The method of claim 13, wherein applying is awet-on-wet technique.
 15. The system of claim 7, wherein the(co)polymers of ethylenically unsaturated monomers comprise at least onemember selected from the group consisting of oligomers, polymers, random(co)polymers, alternating (co)polymers, block (co)polymers, linear(co)polymers, branched (co)polymers, comb (co)polymers, and mixturesthereof.
 16. The system of claim 9, wherein the (co)polymers ofethylenically unsaturated monomers comprise at least one member selectedfrom the group consisting or oligomers, polymers, random (co)polymers,alternating (co)polymers, block (co)polymers, linear (co)polymers,branched (co)polymers, com (co)polymers, and mixtures thereof.
 17. Thesystem of claim 1, wherein component (B) further comprises at least oneconstituent (B2) comprising at least one isocyanate group and at leastone functional group comprising at least one bond activatable by actinicradiation, and wherein constituent (A2) comprises on average threefunctional groups comprising at least one bond activatable with actinicradiation per molecule.